Well construction



P. E. VAUGHAN AND S. M. HALSTEAD.

WELL CONSTRUCTION.

APPLICATION FILED OCT. 13. 1919.

Patented Sept. 14, 1920.

UNITED STATES PATENT orifice.

' rnncy n. VAUGHAN AND s'raunnvm. nans'rmn, or salt JOSE, CALIFORNIA.

WELL cons'mucrron. I

Specification of Letters Patent. Pa',tented Sept. 14, 1920.

Application filed October 18, 1919. Serial No. 880,230.

To all whom it may concern:

Be it known that we, Pnnor E. VAUGHAN and STANLEY M. HALSTEAD citizensof the United States, residing at an Jose, in the county of Santa Claraand State of California, have invented new and useful Improvements inWell' Construction, of which the following is a specification.

' This invention relates to well construction, and,1fiore especially tothe preparation of a well to receive a gravel envelop or lining, such asset forth in our Patent No.

1,289,320, dated Dec. 31st, 1918.

It has become the best practice in deep well drilling in arid andsemi-aridregions' to use the rotary flush drilling method which consistsin supplying a stream of. Water or other freely flowing liquid underfluid which has the effect of preventing caving of the walls indiflicult ground. The discharge is carried off at the top of the well insluices or ditches and empties into a sump from which, after the solidparticles have settled, it is pumped back into the well. Practicallyunlimited depths are thus attained, 500 to 1,000 feet being quite commonin some of the Western States. Should the fluid be not heavy enough tosupport the walls, or, in case the Water filters through and escapes'too fast through the porous seams, mud or clay is added thereto. On theother hand, if the ,fiuid becomes too thick to permit operation of thedrill, the

mud may be removed by the addition of clear water. Clear water weighs62.5 pounds per cubic foot and exerts a pressure of 43 pounds per squareinch, per 100 feet of depth. A good mud weighs 78 pounds per cubic footand exerts a pressure of 53 pounds per square inch, per 100 feet ofdepth.

Water is supplied to the well by means of a pump coupled to the drillpipes and passes out at or near the rotary bit. This water or otherliquid is under considerable pressure and has a decided erosive effecton the loose strata, such as sand and gravel. This action, combined withthe natural caving tendencies of such loose formations, proweeks, itssides pockets chambers therein.

eter can be restored by runmng a full gage bit through the well are'heavily plastered with mud, clay, 'etc., which plaster attains itseatest thickness at the porous seams or oose strata on accountof theTpresence of his coating Wlll often reduce the diameter of the boreseveral inches. Of course, the normal diamreaming out, that is,

after the drilling is completed. This reaming out step will permit thewell casing to be installed, but it will have no effect on the pocketsor chambers formed in the loose strata and which are filled and coatedwith an utterly impervious clay or mud. These I strata being thewater-bearing strata, it is obvious that removal of the coating isnecessary before water can enter the ll. pressure to a rotary bitwhereby to carry off the detritus in solution or suspension. The bore isthus kept filled with'a thick muddy The object then of the presentinvention is to remove the practically impervious deposits or coatingsfrom the walls of the porous strata /and pockets adjoining the 'same andsubstitute therefor a lining or envelop of gravel or other porousmaterial, whereby to insure free passage of water from such strata andthe entrance of the] reaming process as applied to our invention,

In the drawings, 1 is the bore of required dimenslons passing downwardlythrough strata of varying density, 2 indicatin strata of loose materialand 3 the more fixe strata not materially eroded by the action of theflowing water. At 4 are shown annular chambers of various sizes formedin the loose strata 2' by the action of the wash water, the bore 1 andchamber 4 having deposited thereon a layer of fine sand and clay as 5and 6 respectively.

This clay and fine sand-bearing water flowing through the well duringits construction gradually deposits upon the wall of'the well and thewalls of the said chambers -a more or less thick coating of compactmaterial, the coating upon the chamber walls being somewhat thicker thanupon the wall of the well proper because of the eddy formed therein bythe flowing water and because of the fact that the water penetrates theloose formation of the walls of the chambers a distance and deposits itsload 'on said walls as it passes through. In other words,

ourse, upon the nature of the formation and upon the len th of timerequired to complete the bore. Since these chambers are to be filledwith gravel and are to act as receivers for the water in the strata inwhich they are formed, it is clear that the coating of line clay, etc.must be removed before the gravel is installed in order that the saidchambers may function properly and efficiently. Throughout this portionof the construction of the well it is permeated with this thickenedfluid constantly building up the walls thereof by depositing materialthereon. y

In order to secure the full size of the original bore the deposit 5 isreamed out by afull-gaged bit 7, as shown at 8, preparatory toinstalling the casing, so that when the casing 9 is ositioned in thewell the space 10 between 1t and the wall of the well will be asoriginally designed to permit the'passage of gravel therethrough to thelower parts without the formation of keys or arches while the gravel isbeing fed therethrough. After the bore has been reamed and the casing 9placed in position the deposits in the chambers 4 are removed in thefollowing manner. -A plunger 11 is fitted to the drill rod 12 andoperated vertically by means of a power mechanism not shown, the ideabeing to lift the plunger to a considerable height and allow it to dropby gravity. This operation is 'started near the top of the well andresults in agitatingor churning the water both within the casing andbetween it and the wall of the well, and

in the said chambers," thereby stirring up the fine deposit hereinbeforedescribed and equalizing the density of the water by equallydistributing this resuspended matter throughout the agitated water. Asthe plunger works progressively downwardly the walls of all of thechambers are succeswater through the drill rod to the bottom of thewell, the result of this thinning-up process being seen in the dischargeat the top of the well. Since, however, an appreciable length of time isrequired for the water to noticeably affect the character of thedischarge liquid, it results that alower chamber may be washed withcomparatively clear water while gravel is being fed into it through thethicker liquid between it and the top of the well whereby acomparatively proper consistency for sage of the gravel theret rough ata desired .to so control the character of the liquid in the well that itcan be maintained at the ermitting the passrate of speed to insure itsuniform distribution without jamming, and at the same time to mamtam afairly clear body of liquid at the portion of the well in whichthegravel is being deposited. We also prefer to operate the plunger atsuccessively ascending intervals as the gravel is being fed into thewell in order to agitate the water in which the gravel is settlingthereby securing a more equal distribution of the gravel in the saidchambers and connecting spaces-and assisting in preventing the formationof keys and arches. At the same time the clear water will insure theremoval of objectionable deposits from the porous or loose strata. Theplunger is herein shown in one position at 11. Several successivedescending positions are indicated at A-B-CD and E respectively, andseveral successive ascending positions are indicated at F-GH-I and Jrespectively.

It will be understood that the purpose of the equalization process orstep thoroughly equalize the fluid throughout the form a solution ofequal density throughout to dissolve and carry off in'suspension thedeposits formed in thechambers adjacent to the loose strata.Simultaneous with the is. to-

zoo

equalization step clear water may be intro-,

the well and the mixture is thoroughly equalized the thinning up orwashing out process begins. This consists of introducing. v I

clear water through the drill pipe and into the bottom of the well.- Thedistinctive action of clear water compared to that of aparticles andlayers between or amidst argillaceous strata; a thick mud will ratherClear water will produce the opposite effect and tend to plaster up theporous seams.

Preferably the plunger is reciprocated during the admission of clearwater with 95 depth of the well, and to some extent carry the resultthat any deposits of mud or clay remaining in the chambers 4- orotherwise.

. serving to coat the porous seams will be thoroughly washed out.

portion'of the well is thinned or washed out the aveling step may bestarted at once. though the upper portion of the well may at this timecontain a very muddy.

' fluid, it is safe to assume that the bottom of the well where theclear water has been admitted is thorou hly washed and ready to receivegravel. uring the washing out and the introduction of the gravel theplunger is agitated, working progressively from bottom to top as thelevelof the gravel rises. Suchagitation has the e'fiect, in addition towashing the walls of the bore, of

causing the gravel to settle properly and preventing theformation ofkeys or arches.

by the gravel between the casing and the walls of the bore. 'Itisadvantageous to keep the fluid above the level of the gravel as heavy aspossible, inasmuch as it prevents the, walls from caving adjacent theloose strata, and,-by reason of its greater specific gravity, this heavyfluid will, in a way, control the downward movement of the gravel andimpart sufiicient movement thereto to dislodge any keys or arches formedthereby.

It will be. noted that we carryout the equalization step by agitatingthe fluid in the well starting at the top and working progressivelydownward. By so doing, any solid material dislodged near the top andfalling to the bottom will later be dissolved or carried off insuspension when the plunger reaches the bottom. If the-procedure werereversed and the agitation begun at the bottom, then such solid?material as might later be dislodged near the top of the well would fallto the bottom, perhaps to remain there and mix ,with the gravel.

- Moreover, by carrying on-the agitation from top to bottom at this timethe washing out and graveling steps can be started immediately when theplunger reaches the bottom of the well, and thereby we reduce the numberof strips of the plunger from top to bottom, and vice versa. This is ofsome considerable importance from a standpoint of labor saving when itis remembered that these wells approach great depths and to couple anduncouple the necessary number of heavy pipesin attaining such depths isa matter requiring no little time and labor. As at present carried on,the plunger makes one round trip starting at the top and movingprogressively down to equalize the mixture, and thereafter workingprogressively upward when the thinning out and graveling steps are beingcarried on.

It Wlll be understood that owing to varying conditions under which wellsare drilled and constructed the process or method herein described willundergo various changes When the lowertaneously.

to suit these conditions, Therefore we do not limit ourselves to theexact method here- 'in' described and which at present constitutes thepreferred method," but reserve to ourselves the right to vary the methodwithin the scopeof the appended claims.

Owing to the'additional quantity of ,Water necessary to be'obtained frommodern walls for irrigation purposes, the localities in which thisquantity of water can be "obtained from one'stratum are restricted, Toovercome this limitation it has become'more or less common practice tocontinue drilling until a number of different strata have beenpenetrated, and .then connect these up together so that when pumping-youget the benefit of the pressure in a series of strata.

While the present method of construction can easily handle one stratum,it was primarily designed to handle a multiplicity of strata, and thegreat stumbling block in the way of otherexperimenters to date has beento handle successfully a multiplicity of strata with the mud process andat the same time try and fill all voids in the lower strata with apervious material without breaking down the walls of the upper strataand allowing them to cave in against the casing and defeat the end ofproperly preparing the lower strata. It would, naturally be assumed thathad one worked out a dependable ,method of handling one stratum, theoperation of handling a multiplicity of strata would be merely arepetition of the details used in handling the individual stratum, butsuch is not the case in actual practice in this particular method. Priormethods can successfully'handle one stratum with a good roof overhead innumerous cases, as, by using a cone on the bottom of the casing andallowing the wall of gravel surrounding the casing to help shove thiscasing to position.

There are numerous other successful methods which it is unnecessary tomention. But

the point which has apparently been the greatest obstacle in adaptingperforated casing in a gravel filter to successful applicationwherenumerous strata have been encountered has been the fact that after thebore has beenmade to the proper size and whilev the clay is still insuspension in the well this clay must be removed before the ing thisclay the void or vacany must be filled with a pervious material almostsimul- Owing to the law of gravitation, whatever sand stratum or gravelstratum in the well that first breaks down of its own accord, or

is brokendown by outside means, will naturally filter down on theoutside of the casing and combine with the clay and mud solution in thelower cavities and usually becomes almost impossible of removal. Forinstance, if there are five strata in a deep well, and the water can beallowed to enter, and in removstratum nearest the surface broke infirst, the formation from this stratum would filter down on the" outsideof the casing and either bridge ormix in with the mud and clay in thecavities in the lower strata. and defeat the successful development ofwater production in any quantity from these lower strata. Anothernatural law which has to be pro vided against is the fact that the finerthe particles of .which the stratum is composed, and the higherpercentage of voids in the stratum, the easier this stratum will breakdown and disintegrate. Therefore, should one encounter a stratum of finesanhprolific in water content, and a number of feet below encounter astratum of good water-bearing gravel, but considerably larger in sizeand possibly mixed with some fine sand, in developing a wellof this typeby ordinary means the fine stratum (which in this instance would be'the,upper stratum) would break down first and this material would filterdown on the outside of the casing and either mix with the clay solutionin the lower strata (which in this instance are composed of coaiisermaterial%1 and deiieat th? end of pro er y ttin t e rave enve op surrouding t li e cas ing at his point and filling the cavities properly. Thishas always been the greatest drawback to the successful application ofprior patented screens of a vathe high cost of this type of screen, itis always endeavored to use as few lineal feet as possible to obtain thedesired results, and owing to the fact that this screen depends entirelyon its own construction to. properly filter the water from the stratafrom varying degrees of fineness, it has always been customary to orderthis screen for each stratum of the most suitable size mesh, bearing inmind at all times to obtain the largest mesh possible for a givenstratum. Owing to this method of application, should one use a coarsemesh screen for a' lower stratum of coarse water-bearing material, and afine mesh screen for the upper stratum of fine water-bearing material,and then break down the walls of the upper material first, 5b indeveloping the Well, the fine material would filter down on the outsideof the casing and come in through the mesh in the lower coarser screen,making a sandy well which it would be almost impossible to re air. f V paving thus described our invention,-what we claim and desire to secureby Letters Patent is: v

'1. In deep-well construction of the type wherein the bore is keptfilled with a thick fluid throughout the drilling operation and whereina casin of less diameter than the bore is employe and a filling ofgravel or like porous material placed between, the method of preparingthe well for the admisriable mesh type in rotary wells. Owing to- "sionof gravel which consists in agitating said fluid throughout the depth ofthe well whereby to thoroughly equalize the fluid and 'take' up insolution or suspension deposits of non po'rous material formed on thewalls of the bore and in the cavities surrounding the loose strata, saidagitation being carried on progressivelyfrom top to bottom of the well.

2. In deep well construction of the type -wherein the bore is'keptfilled with a thick take up 1n solution or suspension deposits ofnon-porous material formed on the wallsof the bore and the cavitiessurrounding the loose strata and thereafter admitting clear water underpressure to thin up the fluid and. wash out any. remaining deposits ofnon-porous material covering the loose strata, said agitation beingcarried on progressively from top to bottom of the well and thethinning-up and washing out step being carried on progressively frombottom to top of the well and timing the admission of gravel so that assoon as a space is cleaned out it will immediately be filled withgravel.

3. The method of constructing a well which consists in drilling thewell, removing detritus therefrom by hydraulic means, positioningtherein a casing of less diameter than the well, agitating the water inthe well at descending intervals to remove deposits from the wallsthereof, thinning the resulting fluid by the addition of water from theexterior of the well, introducing gravel into the space between saidcasing and the wall of the well, and agitating the thinned fluid atascending intervals corresponding to the rising level of the gravel.

4.-The method of constructing a well which consists in drilling thewell, removing detritus therefrom by hydraulic means, reaming the wallof the well to remove deposits therefrom, positioning therein a casingof less diameter than the well, agitating the water in the well atdescending intervals to more thoroughly cleanse the wallsthereof,-thinning the resulting fluid by the addition of water from theexterior of the well, introducing gravel into the space hetween'thecasing and the wall of the well, and agitating the thinned fluid atascending intervals corresponding to the rising level of the gravel.

5. The method of constructing a well which consists in drilling thewell, removing detritus therefrom by hydraulic means,

reaming the wall of the well to remove dedensity by hydraulic means,-agitating the water in the well and in said casing at dewas:

osits therefrom, positioning therein a perorated casing of less diameterthan the. well, forming chambers in the strata of least density byhydraulic means, agitating the water in the well at descending intervalsto.

remove deposits from said chambers and equalize the density. of saidwater, thinning the resulting fluid by the addition of water from theexterior of the well, introducing gravel into said chambers andconnecting spaces, and agltating the water in which posits therefrom,positioning therein a perforated casing of less diameter than the well,forming chambers in the strata of least scending intervals to removedeposits from said chambers and equalize'the density of- C said water bymeans of a plunger operated 1 said. casing, t

by the addition oi Water-from the. exterior'o'f the well, introducinggravel into said cham-" inning the j resulting fluid bers and connectingspaces, and agitating the water in which'said'gravel isplaced.

-7. The method of constructing a well which consists in drillingthewell', removing detritus therefrom by hydraulic means,

positioning therein a casingoflessgdiameter than the well, agitating thewater in the well at descending intervals andthen at ascendingintervals, and introducing gravel' 'into the well between the saidcasing and the Wall of the well during the. 'second-men tioned agitationof the water therein. In testimony whereof; they have hereunto set theirhands in the presence of two subscribing witnesses. v

PERCY V1 UGH N; STANLEY 'HALSTEAD;

Witnesses: l

N. CALL,

.0. moms;

